Method and apparatus for producing elastomeric nonwoven laminates

ABSTRACT

An apparatus and method for producing an elastomeric nonwoven laminate including a plurality of elastic strands joined to a nonwoven web in a controlled distribution is provided. The apparatus includes an extruder for extruding a plurality of elastic strands onto a cooled surface of a rotating drum, which transports the strands in parallel alignment to a nip formed between two rollers rotating about parallel axis. The drum transfers the plurality of strands to the nip in a controlled distribution where it is bonded with the nonwoven.

FIELD OF THE INVENTION

The present invention relates to a method and apparatus formanufacturing an elastomeric nonwoven laminate. More particularly, thepresent invention relates to an apparatus for manufacturing anelastomeric nonwoven laminate comprising a plurality of elastic strandsand nonwoven material.

BACKGROUND

Disposable fluid-handling articles are often produced on high-speedconverting lines using continuous webs of fabrics, films, foams,elastics, etc. Many of these articles preferably include an elasticregion or component. Typically the elastic component is covered on atleast one side, and preferably two sides, by a nonwoven. Thiscombination of nonwoven and elastic is referred to hereinafter as anelastomeric nonwoven laminate.

Elastomeric nonwoven laminates typically include elastic bonded to anonwoven. The elastic may include elastic film or elastic strands,however, elastic strands are generally preferred over elastic filmssince strands require less material and provide flexibility inarrangement and stretch properties. In one such laminate, a plurality ofelastic strands is joined to a nonwoven while the plurality of strandsis in a stretched condition so that when the elastic strands relax, thenonwoven gathers between the locations where it is bonded to the elasticstrands forming corrugations. The resulting laminate is stretchable tothe extent that the corrugations allow the elastic to elongate. Such alaminate is disclosed in U.S. Pat. No. 4,720,415 to Vander Wielen, etal., issued Jan. 19, 1988.

Elastomeric nonwoven laminates with elastic strands may be produced byextruding a plurality of heated filaments onto a conveyor or rollerwhere the filaments are cooled and transferred to a nonwoven.Alternatively, the plurality of strands may be unwound from a supplyroll and joined to a nonwoven. In either case, arranging the strandsuniformly on the nonwoven can be difficult. The elastic strands aretypically transferred to the nonwoven and bonded by passing thecombination through a nip formed between two rolls. During the transferto the nonwoven, the elastic strands are typically unsupported. Due tovibrations and speed of operation, the strands tend to fall out ofalignment, overlap, entangle, and bundle with neighboring strands. Inaddition the unsupported strands can break or stick to the conveyor andnot transfer to the nonwoven at all. Broken strands can build up onequipment such as a conveyor or transfer roll which eventually resultsin downtime.

Consequently, it would be beneficial to provide a method and apparatusfor producing an elastomeric nonwoven laminate that is capable ofplacing the plurality of continuous elastic strands in a controlleddistribution on the mating nonwoven. In addition, it would be beneficialto provide a method and apparatus capable automatically capturing andthreading elastic strands that fail to transfer to the nonwoven.

SUMMARY OF THE INVENTION

The present invention provides an apparatus and method for producing anelastomeric nonwoven laminate including a plurality of elastic strandsbonded to a nonwoven web in a controlled distribution. The apparatusincludes an extruder for extruding a plurality of elastic strands on acooled surface of a drum, which conveys the plurality of strands to afirst roller forming a nip with a second roller. The first nonwoven issupplied from a first nonwoven source to the second roller. The firstroller is positioned close to the cooled surface of the drum to receivethe plurality of elastic strands while allowing for a minimal span ofunsupported strands during the transfer. The apparatus may include asecond nonwoven source supplying a second nonwoven having a secondbonding surface to the first roller forming the nip with the secondroller. For this embodiment, the plurality of elastic strands isconveyed directly onto the second bonding surface as the second nonwovenpasses over the first roller. The first and second nonwovens passthrough the nip in a face-to-face arrangement at second velocity V2sandwiching the elastic strands therebetween conveyed from the cooledsurface of the drum at first velocity V1 where V2 is greater than V1.

In a preferred embodiment, the apparatus includes an idler rollerlocated proximate to the cooled surface of the drum counterclockwisefrom the point where the plurality of strands are transferred to thefirst roller. The idler roller directs the first bonding surface of thefirst nonwoven into contact with the cooled surface of the drum enablingthe first bonding surface to remove elastic strands that stick to thecooled surface of the drum and fail to transfer to the first roller.After having swept the cooled surface of the drum, a pivot rollerlocated adjacent to the second roller forming the nip, reverses thedirection of the first nonwoven enabling any strands collected on thefirst bonding surface to be expelled therefrom. A series of rollersdirects the first nonwoven first away from the pivot roller and thenback around to the second roller forming the nip by first passing thefirst bonding surface beneath the pivot roller to recollect the elasticstrands expelled at the pivot roller. Sweeping the cooled surface of thedrum not only keeps the drum surface clean of elastic strands, but alsoprovides a means for threading the plurality of elastic strands to thefirst roller during start up.

In an alternate embodiment, an elastomeric nonwoven laminate comprisinga first and second nonwoven sandwiching a plurality of elastic strandstherebetween can be made to proceed from the nip to at least two pairsof rollers forming S-wraps. The first pair of rollers forming the S-wraprotates at a speed providing a surface speed which is approximatelyequal to V2. The second pair of rollers forming the S-wrap rotates at aspeed providing a surface speed V3 that is greater than V2. Theacceleration overstrains the laminate resulting in additional stretch.

BRIEF DESCRIPTION SHOWN IN THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter that is regarded as thepresent invention, it is believed that the invention will be more fullyunderstood from the following description taken in conjunction with theaccompanying drawings. None of the drawings are necessarily to scale.

FIG. 1 is a schematic side elevation view of an apparatus for laminatinga nonwoven and a plurality of strands of elastic forming an elastomericnonwoven laminate according to the present invention.

FIG. 2 is a schematic side elevation view of an apparatus for laminatinga first nonwoven and a second nonwoven with a plurality of elasticstrands sandwiched in between.

FIG. 3 is a schematic side elevation view of the apparatus in FIG. 2including features which enable the first nonwoven to swipe the drumclean of residual elastic strands in advance of joining with theplurality of elastic strands at the nip,

FIG. 4 a is a side view of the elastomeric nonwoven laminate produced onthe apparatus depicted in FIGS. 1 through 3.

FIG. 4 b is a cross sectional view of the elastomeric nonwoven laminatedepicted in FIG. 4 a.

DETAILED DESCRIPTION OF THE INVENTION

The method and apparatus of the present invention are designed toprovide a more consumer desirable elastomeric nonwoven laminate suitablefor use in a variety of articles including a disposable fluid-handlingarticle. The elastomeric nonwoven laminate comprises a nonwoven andelastic composed from at least one layer of a plurality of elasticstrands and at least one layer of a nonwoven material. The method andapparatus are capable of efficiently producing an elastomeric nonwovenlaminate having a controlled distribution of elastic strands.

Definitions

The following terminology is used herein consistent with the plainmeaning of the terms with further details provided in the presentspecification.

“Live stretch” includes stretching elastic and bonding the stretchedelastic to a nonwoven. After bonding the stretched elastic is releasedcausing it to contract, resulting in a “corrugated” nonwoven. Thecorrugated nonwoven can stretch as the corrugated portion is pulled toabout the point that the nonwoven reaches at least one original flatdimension.

“Continuous filaments” refers to strands of continuously formedpolymeric filaments. Such filaments are formed by extruding moltenmaterial through a die head having a certain type and arrangement ofcapillary holes therein.

“Controlled distribution” refers to a parallel arrangement of elasticstrands having no overlapping or bundles of strands where the variationin distance between the elastic strands from the point of extrusion tothe point of lamination is minimal.

A “converting facility” refers to any production equipment producing oneor more components of a disposable fluid-handling article that aresubsequently assembled into a finished disposable fluid-handlingarticle. It may also produce a finished disposable fluid-handlingarticle that is complete for use by a consumer.

An “elastic,” “elastomer” or “elastomeric” refers to polymers exhibitingelastic properties. They include any material that upon application of aforce to its relaxed, initial length can stretch or elongate to anelongated length more than 10% greater than its initial length and willsubstantially recover back to about its initial length upon release ofthe applied force.

An “extrusion apparatus” or “extruder” refers herein to any machinecapable of extruding a molten stream of material such as a polymericthrough one or more extrusion dies.

The term “extrude” or “extruding” refers herein to a process by which aheated elastomer is forced through one or more extrusion dies to form amolten stream of elastic that cools into a solid.

The term “molten stream” refers herein to a linear deposit of a heatedliquid material such as a polymeric exiting an extrusion apparatus. Thestream may include continuous filaments, discontinuous fibers, orcontinuous films of a polymeric material. When cooled, the molten streamforms an elastic strand.

The term “joined” herein encompasses configurations whereby a materialor component is secured directly or indirectly (by one or moreintermediate members) to another material or component. An example ofindirect joining is an adhesive. Direct bonding includes heat and orpressure bonding. Joining may include any means known in the artincluding, for example, adhesives, heat bonds, pressure bonds,ultrasonic bonds, and the like.

The term “nonwoven” refers herein to a material made from continuous(long) filaments (fibers) and/or discontinuous (short) filaments(fibers) by processes such as spunbonding, meltblowing, and the like.Nonwovens do not have a woven or knitted filament pattern.

Nonwovens are typically described as having a machine direction and across direction. The machine direction is the direction in which thenonwoven is manufactured. The cross direction is the directionperpendicular to the machine direction. Nonwovens are typically formedwith a machine direction that corresponds to the long or rolleddirection of fabrication. The machine direction is also the primarydirection of fiber orientation in the nonwoven.

FIG. 1 shows a side view of an apparatus 100 according to the presentinvention for producing elastomeric nonwoven laminate 20. The apparatus100 includes a drum 110 rotating about an axis 114 and having a surfacespeed V₁. The drum 110 is glycol cooled to provide a cooled externalsurface 112. The temperature of the cooled external surface ismaintained between 0° C. and 5° C. For orientation purposes, the drum110 has a first quadrant 111 a between 12 o'clock and 3 o'clock, asecond quadrant 111 b between 3 o'clock and 6 o'clock, a third quadrant111 c between 6 o'clock and 9 o'clock, and a fourth quadrant 111 dbetween 9 o'clock and 12 o'clock.

The drum 110 can be sized to accommodate any size laminate or processset up. For instance a larger drum 110 may be utilized for offlinematerial production operations where the elastomeric nonwoven laminateis stored on a roll or in a box for future use. Smaller drum sizes maybe required for online operations incorporated upstream of a convertingoperation. For offline operations, the diameter of the drum may beapproximately one meter or larger, whereas for online operations thediameter of the drum may be approximately 0.5 meters or less. Similarlyfor offline operations, the width of the drum may be approximately onemeter or larger whereas for online operations the width of the drum maybe limited to approximately one meter or less. The rotation of the drum110 can be powered by a variable speed motor capable of ramping up ordown depending on the operator's demand.

The apparatus 100 includes an extruder 120 for extruding a molten streamof elastomeric polymer. The extruder 120 extrudes the molten stream ofpolymer through a plurality of nozzles 122 forming a plurality ofelastic strands 23 that flow in parallel alignment onto the cooledsurface 112 of the rotating drum 110. Preferably, the elastic strandsare extruded onto the cooled surface 112 of the drum 110 such that thedistance between any two adjacent strands ranges between about 1 mm andabout 3 mm. More preferably, the distance between any two adjacentstrands is about 1.5 mm. The extruder 120 is mounted between the firstand fourth quadrants 111 a, 111 d and deposits the plurality of strands23 onto the cooled surface 112 of the drum 110 near 12:00 o'clock.

The extruder 120 preferably includes a built in metering pump, valve andnozzle arrangement wherein the metering pump and valve are positioned inproximity to the nozzle in order to provide a controlled discharge ofpolymer. The controlled discharge of polymer ensures that an adequatesupply of polymer is supplied to the cooled surface of the drumparticularly during starts and stops. Excessive flow of polymer duringstops can cause localized heating of the cooled surface of the drumwhich can lead to polymer build up caused by the elastic strandssticking to the surface of the drum.

First and second rollers 130, 132 are mounted near the cooled surface112 of the drum 110 at the third quadrant 111 c. The first and secondrollers 130, 132 rotate about two parallel axes forming a nip 134therebetween, where each provides a surface speed V2. The surface speedV2 of each of the rollers is greater than the surface speed V1 of thedrum.

The first roller 130 is positioned proximate to the cooled surface 112of the drum 110 to minimize the span 150 of unsupported strandstransferring from the cooled surface 112 of the drum 110 to the firstroller 130. Preferably, the first roller is positioned as close to thecooled surface of the drum as possible without actually making contact.The actual measured distance separating the two depends upon the sizesof the drum and the first roller. For instance, for a drum diameter of 1meter and a first roller diameter of 150 mm, the distance between thecooled surface 112 of the drum 110 and the first roller 130 can rangefrom approximately 0.5 mm to about 5 mm. The corresponding length of thespan 150 of unsupported strands can range from about 18 mm to about 75mm. For smaller size drums, the length of the span 150 of unsupportedstrands can be shorter. For instance, a 0.5 meter diameter drum with a150 mm first roller 130 can enable the first roller 130 to be positionedas close as 1 mm to the cooled surface 112 of the drum 110 and limit thelength of the span 150 of unsupported strands to about 22 mm.

The first roller 130 receives the plurality of strands 23 near thecooled surface 112 of the drum 110, minimizing the span 150 ofunsupported strands between the cooled surface 112 of the drum 110 andthe first roller 130. Preferably, the plurality of strands 23 transfersfrom the cooled surface 112 of the drum 110 to the first roller suchthat the strands are approximately tangent to both the cooled surface ofthe drum and the surface of the first roller 130 and the length of thespan 150 of unsupported elastic strands 23 is minimal, ranging betweenabout 10 mm and about 200 mm. Preferably, the length of the span 150 ofunsupported elastic strands 23 during the transfer ranges between about20 mm and about 50 mm. By minimizing the length of the span ofunsupported strands during the transfer, the elastic strands can betransferred to the first roller in a controlled distribution where thedistance measured between any two adjacent strands varies 30% or lessfrom the point of extrusion to the point of lamination. For instance, ifthe original spacing at the extruder is set at 1 mm, the spacing betweenany two adjacent strands will range between 0.7 mm to 1.3 mm.

A first nonwoven source 140 supplies a first nonwoven 21 having a firstbonding surface 22 to the second roller 132 forming the nip 134 with thefirst roller 130. A first adhesive source 142 positioned between thefirst nonwoven source 140 and the second roller 132 applies adhesive tothe first bonding surface 22. The first nonwoven 21 and the plurality ofelastic strands 23 pass between the nip 134 formed by the first andsecond rollers 130, 132 forming the laminate. The difference in velocitybetween surface velocity V1 of the cooled surface 112 of the drum 110and the surface velocity V2 of the first and second rollers 130, 132strains the plurality of elastic strands 23 at the nip. Once the swainis relieved from the strands, corrugations form in the nonwovenproviding an elastomeric nonwoven laminate 20.

Upon exiting the nip 134, the elastomeric nonwoven laminate 20 may beconveyed directly to a converting operation which manipulates thelaminate to form a component of a disposable absorbent article such asan elastic waist band, an elastic cuff or an elastic side panel.Alternatively, the elastomeric nonwoven laminate 20 may be joined with asecond nonwoven or other material and stored on a roll or in a box forfuture use.

Exposed adhesive on the first bonding surface 22 between the elasticstrands 23 resulting from the process of joining the plurality ofstrands 23 to the first bonding surface 22 can hinder any down streamconverting operation and can make storing the elastomeric nonwovenlaminate on a roll virtually impossible. Consequently, it is preferredto cover the elastic strands 23 that are exposed on the first bondingsurface 22 of the first nonwoven 21. Such covering may include aflexible release paper joined to the first bonding surface 22 downstreamof the nip 134. The release paper can enable the laminate to be storedon a roll and can be removed in a subsequent operation.

Alternatively, a second nonwoven source 160 may be provided supplying asecond nonwoven 24 to be joined with the first nonwoven 21 and pluralityof elastic strands 23. As shown in FIG. 2, the second nonwoven source160 supplies a second nonwoven 24 having a second bonding surface 25 tothe first roller 130 forming the nip 134 with the second roller 132. Asecond adhesive source 162 positioned between the second nonwoven source160 and the first roller 130 applies adhesive to the second bondingsurface 25. The first and second nonwovens 21, 24 pass between the nip134 formed by the first and second rollers 130, 132 sandwiching theplurality of elastic strands 23 therebetween. At the nip 134, a firststrain is produced on the elastic strands 23 as a result of beingextended in the machine direction 40. The strain is induced as a resultof the difference in velocity between the elastic strands 23 travelingon the cooled surface 112 of the drum 110 at first velocity V1 and thefirst and second nonwovens 21, 24 traveling on the second and firstrollers 132, 130, respectively, at second velocity V2. The greater thevelocity differences between the first velocity V1 and the secondvelocity V2, the greater the resulting strain. For the presentinvention, the difference in velocity creates a strain on the pluralityof elastic strands 23 ranging from about 20° to about 500°.

Upon exiting the nip 134, the extensibility of the elastomeric nonwovenlaminate can be further enhanced by overstraining the web. For instance,in the embodiment shown in FIG. 2, the elastomeric nonwoven laminate 20is exposed to a second strain by passing the laminate through at leasttwo pairs of rotating rollers 210, 220 forming S wraps downstream of thenip 134. The first pair of rollers 210 forming the first S wrap 212provides a surface speed V2 and the second pair of rollers 220 formingthe second S wrap 222 provides a surface speed V3 which is greater thanV2. The increase in velocity experienced by the laminate as it isconveyed through the S wraps 212, 222 overstrains the laminate 20 whichcan increase the extensibility of the laminate at least 20%

Conveying elastic strands from the extruder to the first roller via arotating drum is difficult to maintain over an extended period of timeas a result of buildup on the drum caused by elastic strands having thetendency to break and stick to the surface of the drum failing totransfer to the first roller. In addition, manual threading of theelastic strands from the cooled surface of the drum to the first rolleris often required at start up since the light weight of the elasticstrands causes them to stick to the surface of the drum rather thanautomatically making the transfer onto the first roller. Consequently,an alternate embodiment is provided in FIG. 3 including an additionalapparatus for maintaining the cleanliness of the roll during normaloperation and automatically threading the strands during start up.Although the embodiment illustrated in FIG. 3 produces an elastomericlaminate comprising a first and second nonwoven 21, 24 the apparatus isequally applicable to the apparatus illustrated in FIG. 1 for making anelastomeric nonwoven laminate comprising a single nonwoven.

As shown in FIG. 3, an idler roller 170 is positioned between the firstnonwoven source 140 and the second roller 132, which is disposedadjacent to the second quadrant 111 b of the cooled surface 112 of thedrum 110. The idler roller 170 directs the first bonding surface 22 ofthe first nonwoven 21 into contact with the cooled surface 112 of thedrum 110 in advance of reaching the second roller 132. By making contactwith the cooled surface 112 of the drum 110, the first bonding surface22 can remove elastic strands that stick to the cooled surface 112 ofthe drum 110 and fail to transfer to the nip 134 formed by the first andsecond rollers 130, 132.

After removing stray strands from the cooled surface 112 of the drum110, the first nonwoven 21 can be made to proceed to a pivot roller 180located adjacent to the second roller 132 forming the nip 134, a selectdistance from the idler roller 170. The pivot roller 180 can be arrangedto force the first nonwoven 21 in a reverse direction near the secondroller 132 causing any stray strands collected from the cooled surface112 of the drum 110 to expel from the first bonding surface 22. Thepivot roller is preferably small having a diameter which is less thanabout 20 mm. In an alternate embodiment, the pivot roller can bereplaced with a static plate or sheet, however, a roller is preferredsince a static plate or sheet can induce strain on the nonwoven causingnecking.

From the pivot roller 180, the first nonwoven 24 can be made to proceedto a series of rollers 190. The series of rollers 190 are arrangedrelative to the pivot roller 180 such that the angle 185 between firstnonwoven 21 approaching the pivot roller 180 and the first nonwoven 21departing the pivot roller 180 ranges from 0 degrees to 90 degrees. Asshown in FIG. 3, the series of rollers 190 directs the first nonwoven 21first away from the pivot roller 180 and then back to the second roller132 forming the nip 134 along a path which passes the first bondingsurface 22 beneath the pivot roller 180 so that any strands expelledfrom the first bonding surface 22 at the pivot roller 180 can berecollected onto the first bonding surface 22 prior to reaching thesecond roller 132. The series of rollers 190 can also be arranged todirect the first nonwoven 21 to a first adhesive applicator 142 applyinga first adhesive to the first bonding surface 22 prior to passingbeneath the pivot roller 180.

Forcing the first bonding surface 22 of the first nonwoven 21 to makecontact with the cooled surface 112 of the drum 110 in the secondquadrant 111 b has other advantages such as enabling the apparatus toautomatically thread itself during initial start up. During initialstart up, the elastic strands 23 are not heavy enough to automaticallyseparate from the cooled surface 112 of the drum 110 and transfer to thefirst roller 130. As a result, the elastic strands 23 stick to thecooled surface 112 of the drum 110, bypassing the first roller 130 inthe third quadrant 111 c. By forcing the first bonding surface 22 intocontact with the cooled surface 112 of the drum 110 in the secondquadrant 111 b, the elastic strands 23 are removed from the cooledsurface 112 of the drum 110 and redirected to the nip 134 formed betweenthe first and second rollers 130, 132.

In one embodiment, the plurality of elastic strands 23 sandwichedbetween the first and second nonwovens 21, 24 are exposed to a secondstrain by passing the elastomeric laminate through at least two pairs ofrotating rollers 200 forming S wraps positioned downstream of the nip134. The first pair of rollers 210 forming the first S wrap 212 providesa surface speed V2 and the second pair of rollers 220 forming the secondS wrap 222 provides a surface speed V3 that is greater than V2. Theincrease in velocity overstrains the laminate 20 which can increase theextensibility of the laminate at least 20%.

An elastomeric nonwoven laminate produced using the apparatus and method0f the present invention is illustrated in FIGS. 4 a and 4 b. FIG. 4 ashows, in exaggerated form, the corrugation of the first and secondnonwovens 21, 24 with corrugation hills 28 and corrugation valleys 29that occur after the first and second nonwovens 21, 24 are joined to theelastic strands 23 via adhesive 30, 32, respectively. Corrugation isused to describe irregular corrugation hills 28 end corrugation valleys29 that alternate. As shown, the first and second nonwovens 21, 24 arecorrugated in the cross direction 45 with the corrugation hills 28 andcorrugation valleys 29 alternating in the machine direction 40. Once astrain is placed on the elastomeric laminate 20 in the machine direction40, the corrugations enable the first and second nonwovens 21, 24 toextend with the plurality of elastic strands 23 at least to the point ofreaching the force wall, which is about where the corrugations flattenout. As the strain is removed, the plurality of elastic strands 23contact back toward their original, relaxed length. This contractioncauses the observed first and second nonwoven 21, 24 corrugations.

Strain is measured as the percent of length increase in the plurality ofelastic strands 23 under load. For example a strand with a free andstretchable strand length of 15 centimeters (cm) may have a load appliedsuch that the 15 cm strand elastic is now 18 cm long. This lengthincrease of 3 cm is 20% of 15 cm ( 3/15), or a 20% strain. Theelastomeric nonwoven 20 produced according to the present invention mayhave a strain ranging from about 20% to about 500%, preferably fromabout 100% to about 400%, and more preferably from about 200% to about400%.

Since the primary function of the elastomeric nonwoven laminate 20 is tobe stretchable, the elastomeric nonwoven laminate 20 is capable of atleast a 50% strain prior to reaching the force wall. Although the forcewall has generally been described as the point where the corrugationsnearly flatten out, the force wall typically occurs when the forcerequired for a 10% increase in strain increases at least about 20%.Depending upon design choice and the particular application of theelastomeric nonwoven laminate, the elastomeric nonwoven laminate 20 canbe made to endure a strain greater than 50%, 100%, 200%, or 300% priorto reaching the force wall. Preferably, the elastomeric nonwovenlaminate 20 produced according to the present invention is capable of atleast a 100% strain prior to reaching the force wall. More preferably,the elastomeric nonwoven laminate 20 is capable of at least a 200%strain prior to reaching the force wall.

The first nonwoven 21 and the second nonwoven 24 may comprise anynonwoven material known in the art. The first nonwoven 21 and the secondnonwoven 24 may comprise fibers made of polypropylene, polyethylene,polyester, nylon, cellulose, polyamide, or combinations of suchmaterials. Fibers of one material or fibers of different materials ormaterial combinations may be used in the first and/or second nonwoven21, 24.

Any process known in the art may be used to make the first nonwoven 21and/or the second nonwoven 24. Exemplary processes include spunbond,spunbond meltblown spunbond (SMS), spunbond meltblown meltblown spunbond(SMMS), carded and the like. Particularly acceptable nonwovens includehigh elongation carded (HEC) nonwovens and deep activation polypropylene(DAPP) nonwovens.

The first nonwoven 21 and the second nonwoven 24 may comprise fibersthat are bonded internally, including fibers that are needle punched,hydro entangled, spun bonded, thermally bonded, bonded by various typesof chemical bonding such as latex bonding, powder bonding, and the like.Preferably, the basis weight of the first nonwoven 21 and/or secondnonwoven 24 is in the range of about 10 gsm to about 30 gsm.

The elastic strands 23 preferably extend in a parallel uniformly spacedarrangement between the first nonwoven 21 and the second nonwoven 24.However, the elastic strands 23 may be arranged in any configurationdesired. For instance, the strands may be arranged to provide a specificforce profile in the elastomeric nonwoven laminate 20 by varying thethickness of the individual strands or the spacing between them.

In addition, the shape of the elastic strands 23 is not limited. Forexample, typical elastic strands 23 have a circular cross sectionalshape, but sometimes the plurality of elastic strands may have differentshapes, such as a trilobal shape, or a flat (i.e., “ribbon” like) shape.Further, the thickness or diameter of the elastic strands 23 may vary inorder to accommodate a particular application.

The plurality of elastic strands 23 is preferably made of a resilientlyelastic thermoplastic material. The elastic strands may be made fromliquid elastic that can be extruded through a die to achieve a desiredstrand elastic diameter and/or shape. The elastic strands are preferablystyrene block copolymers, polyurethane or latex rubber having a diameterranging between about 0.15 mm and about 0.5 mm and a density rangingfrom about 600 kg/m³ to about 1250 kg/m³.

Although the first nonwoven 21, second nonwoven 24 and plurality ofelastic strands 23 have been described as adhesively bonded, they may bejoined by any joining means known in the art. Some examples of suitablejoining means and/or methods for joining include, but are not limitedto, adhesives, cohesives, thermal bonding, pressure bonding, mechanicalbonds, ultrasonic bonding, radio frequency bonds and/or any combinationof any known methods of joining such materials.

All documents cited herein are, in relevant part, incorporated herein byreference; the citation of any document is not to be construed as anadmission that it is prior art with respect to the present invention.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1. An apparatus for producing a nonwoven elastomeric laminate composedof at least one nonwoven and a plurality of elastic strands, theapparatus comprising: a) a surface cooled drum rotating about an axisand having a surface speed V₁, the surface cooled drum having a firstquadrant between 12 o'clock and 3 o'clock, a second quadrant between 3o'clock and 6 o'clock, a third quadrant between 6 o'clock and 9 o'clock,and a fourth quadrant between 9 o'clock and 12 o'clock; b) an extruderextruding a plurality of elastomeric strands in parallel alignment ontothe cooled surface of the drum between the first and second quadrants;c) first and second rollers forming a nip therebetween wherein the firstroller is positioned proximate to the cooled surface of the drum, thefirst and second rollers each having a surface speed V₂ wherein thesurface speed V₂ is greater than the surface speed V₁, wherein the drumtransfers the plurality of elastic strands to the first roller wherein aspan of unsupported strands between the cooled surface of the drum andthe first roller is minimized to provide a controlled distribution ofelastic strands entering the nip; d) a first nonwoven source supplying afirst nonwoven having a first bonding surface to the second rollerforming the nip; e) a first adhesive source for applying adhesive to thefirst bonding surface in advance of the nip, f) an idler rollerpositioned adjacent to the cooled surface of the drum between the firstnonwoven source and the second roller, the idler roller directing thefirst bonding surface to make contact with the cooled surface of thedrum so that the first bonding surface removes strands from the cooledsurface of the drum that inadvertently fail to transfer to the firstroller forming the nip; g) a pivot roller located adjacent to the secondroller that forms the nip a select distance from the idler roller, thepivot roller enabling the first nonwoven to reverse direction near thesecond roller causing the strands collected from the cooled surface ofthe drum to expel from the first bonding surface; and h) a series ofrollers positioned near the pivot roller, the series of rollers arrangedto direct the first nonwoven first away from the pivot roller and thenback to the second roller forming the nip while passing the firstbonding surface beneath the pivot roller to collect the broken elasticstrands expelled at the pivot roller onto the first bonding surfaceprior to entering the nip.
 2. The apparatus according to claim 1 whereinthe extruder comprises a built in metering pump, valve and nozzlearrangement wherein the metering pump and valve are positioned inproximity to the nozzle to provide a controlled discharge of polymer,limiting the flow of polymer during starts and stops.
 3. The apparatusaccording to claim 1 wherein the span of unsupported strands between thecooled surface of the drum and the first roller is tangent to both thecooled surface of the drum and the first roller.
 4. The apparatusaccording to claim 1 wherein the span of unsupported strands between thecooled surface of the drum and the first roller is between about 10 mmand about 200 mm.
 5. The apparatus according to claim 1 wherein the spanof unsupported strands between the cooled surface of the drum and thefirst roller is between about 20 mm and about 50 mm.
 6. The apparatusaccording to claim 1 wherein the idler roller and pivot roller arearranged in sequence such that the first bonding surface of the firstnonwoven contacts the cooled surface of the drum in the second quadrantbetween the idler roller and the pivot roller.
 7. The apparatusaccording to claim 1 wherein the series of rollers are arranged relativeto the pivot roller such tat the angle between first nonwovenapproaching the pivot roller and the first nonwoven departing the pivotroller ranges from 0 degrees to 90 degrees.
 8. The apparatus accordingto claim 1 wherein a distance measured between any two adjacent elasticstrands joined to the first bonding surface of the first nonwoven variesless than 30% from the distance measured between the same two adjacentelastic strands extruded from the extruder in parallel alignment ontothe cooled surface of the drum.
 9. The apparatus according to claim 1further comprising a second nonwoven source supplying a second nonwovenhaving a second bonding surface to the first roller forming the nip,wherein the first and second bonding surfaces of the first and secondnonwovens are joined in a face-to-face arrangement at the nip,sandwiching the plurality of elastic strands therebetween in acontrolled distribution.
 10. The apparatus according to claim 9 furthercomprising a second adhesive source located between the second nonwovensource and the first roller forming the nip for applying adhesive to thesecond bonding surface in advance reaching the nip.
 11. The apparatusaccording to claim 9 further comprising at least two pairs of rollersforming two S wraps positioned in sequence with the nip wherein therotation of the first pair of rollers provides a surface speed V2 andwherein the rotation of the second pair of rollers provides a surfacespeed V3 which is greater than V2.
 12. The apparatus according to claim11 wherein the S wraps overstrain the elastomeric nonwoven laminate,increasing the extensibility by at least 20%.